<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
    <style>
        .work {
            width: 200px;
            height: 200px;
            border: 1px solid red;
            background: green;
            border-top: 2px dotted blue;
            border-bottom: 3px dashed green;
        }

        div:hover {
            box-shadow: 10px 10px 30px 20px red;
        }

        input {
            border-top: 2px dotted blue;
        }

        #d1 {
            width: 200px;
            height: 200px;
            border: 1px solid blue;
        }
    </style>
    <!--:hover是什么意思？ -->
</head>
<body>
<div class="work"></div>
<div id="d1"></div>
<!--<script>-->
<!--$('.work').mouseover(function () {-->
<!--$('.work').css('box-shadow','10px 10px 30px 20px red');-->
<!--});-->
<!--</script>-->
</body>
</html>